• Journal of the Korean Society of Radiology
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• v.83 no.6
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• pp.1259-1272
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• 2022

Purpose As part of ongoing efforts to improve the current e-learning center, a survey was conducted regarding user experience and satisfaction to identify areas of improvement. Materials and Methods Radiologists (n = 454/617) and radiology residents (n = 163/617) of the Korean Society of Radiology were asked to answer a survey via email. The questionnaire asked for basic user information as well as user experiences relating to the e-learning center, such as workplace, frequency of use, overall satisfaction levels, reasons for satisfaction or dissatisfaction, and other suggestions for improvement. Results Annual members and all members of the e-learning center reported above average satisfaction levels of 67% and 42%, respectively. Approximately 30% of respondents viewed e-learning center lectures more than 5 times a month, with residents having a particularly high usage frequency. There was a high demand for additional lectures covering more diverse specialties (e-learning for annual members only: n = 28/97, e-learning for all members: n = 72/166), a smoother and more convenient searching platform/interface (n = 37/97 and n = 58/166, respectively), and regular content updates. In addition, many of the members suggested the addition of user-friendly functions such as playback speed control, a way to save viewing history, as well as requests for improved system stability. Conclusion Based on survey results, the educational committee plans to continue its efforts to improve the e-learning center by increasing the quality and quantity of available lectures, and increasing technical support to improve the stability and convenience of the e-learning digital system.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.35 no.1
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• pp.73-96
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• 2024

This study aimed to establish a systematic and comprehensive operational plan for the library to be constructed in the Gwacheon Knowledge Information Town. To achieve this, a survey on the demand for library operations was conducted among actual users of the Gwacheon City Public Library, and plans for the library collection development, user services, and methods to revitalize use were formulated based on the survey results. The findings are as follows. First, the library's construction/space analysis results suggest the need for a multifunctional cultural space accessible to everyone, serving as both a relaxation area and venue for a free information exchange and communication, allowing for a certain level of noise to facilitate an open atmosphere for users. Second, the analysis of the preferred types and forms of library materials revealed that printed materials ranked first, followed by web resources in the second place, and e-books/e-journals in the third. Additionally, there was a high preference for subjects such as literature and history. Third, a high preference was observed for cultural and arts programs, indicating the need for the future Gwacheon Knowledge Information Town Library to strengthen and implement programs focusing on cultural and artistic themes.

• Journal of Korea Water Resources Association
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• v.57 no.2
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• pp.139-150
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• 2024

This study introduced a method of estimating water surface evaporation using the physical-based Penman combination equation (PCE) and the Penman wind function (PWF). A set of regression parameters in the PCE and PWF models were optimized by using the observed evaporation data for the period 2016-2017 in the Yongdam Dam watershed, and their effectiveness was explored. The estimated evaporation over the Deokyu Mountain flux tower demonstrated that the PWF method appears to have more improved results in terms of correlation, but both methods showed overestimation. Further, the PWF method was applied to the observed hydro-meteorological data on the surface of Yongdam Lake. The PWF method outperformed the PCE in the estimation of water surface evaporation in terms of goodness-of-fit measure and visual evaluation. Future studies will focus on a regionalization process which can be effective in estimating water surface evaporation for the ungauged area by linking hydrometeorological characteristics and regression parameters.

• Composites Research
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• v.37 no.2
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• pp.101-107
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• 2024

Demand for submarine cable is increasing due to advances in submarine power transmission technology and submarine cable manufacturing technology. Submarine cable use various types of protective equipment to prevent problems such as high maintenance costs in the event of cable damage and power outages during maintenance periods. Among them, flexible protection tube is a representative protective equipment to protect cables and respond to external forces such as waves and current. The flexible protection tube is made of polyurethane 85A hyperelastic material, so the calculation of mechanical behavior is carried out using mechanical properties based on experimental results. In this study, a study was conducted to determine the bending performance and tensile performance of flexible protection tube through analytical methods. The physical properties obtained through the multiaxial tensile test of polyurethane 85A were used for the analysis. Bending and tensile performance were determined for the maximum bending moment standard of 15 kN·m and the tensile load standard of 50 kN. As a result, it was confirmed that when the maximum bending moment of 15 kN·m of the flexible protection tube occurred, the bending performance of the MBR was secured at 13 m and when a tensile load of 50 kN, it was applied the maximum vertical displacement was 968 mm, confirming that the tensile performance was secured.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.4
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• pp.365-372
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• 2024

The South Korean marine industry is emerging as a significant market, driven by the growing popularity of various water leisure activities, including sailing. This trend suggests a rising demand for sailing yachts. Consequently, since 2022, the design and development of a 28ft sailing yacht have been ongoing, supported by the government and the Ministry of Oceans and Fisheries, to promote yachting culture in South Korea. The Velocity Prediction Program (VPP) analysis was conducted using WinDesign during the preliminary design stage to evaluate performance and determine design parameters. The hydrodynamic model used for this vessel is based on regression methods developed from years of experience in naval architecture and yacht research at the Wolfson Unit, providing reliable estimates for most modern yachts. However, owing to the lack of specific hydrodynamic data from towing tank tests or CFD numerical analysis, verification of the hydrodynamic model has faced some challenges. Additionally, an incomplete weight estimate resulted in variable VCG values, potentially affecting stability and overall performance. The optimal boat speed for this vessel was determined at true wind speeds (TWS) of 4, 8, 12, 16, and 20 knots, using both the jib (up to 120° TWA) and the spinnaker (from 80° TWA). The optimized speed of the yacht was found to be comparable to that of international similar-class yachts.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.4
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• pp.123-138
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• 2024

This study aimed to examine the effects of leisure activities on leisure satisfaction and job satisfaction among airline cabin crew, as well as the mediating effect of leisure satisfaction. The context for this research was the sudden increase in air travel demand in 2022 following the COVID-19 economic recovery, which led to cabin crew members experiencing severe stress and fatigue due to excessive scheduling. To achieve this research objective, a self-administered online survey was conducted with 251 cabin crew members from domestic and international airlines, resulting in a total of 224 valid leisure satisfaction and job satisfaction, as well as the mediating effect of leisure satisfaction on the relationship between leisure activity types and job satisfaction. The hypothesis testing results revealed that all types of leisure activities, including family-oriented, friend-oriented, and work-related activities, had a significant positive effect on leisure satisfaction. Family-oriented and work-related leisure activities had a significant positive effect on job satisfaction, and leisure satisfaction had a significant positive effect on job satisfaction. Additionally, the mediation analysis confirmed that leisure satisfaction partially mediated the relationship between family-oriented and work-related leisure activities and job satisfaction, while it fully mediated the relationship between friend-oriented leisure activities and job satisfaction. Therefore, the study offers academic implications based on these findings and proposes strategies for utilizing various types of leisure activities to enhance leisure satisfaction and job satisfaction among airline cabin crew. It also suggests that future research should further validate these findings through methods such as the Delphi technique or Analytic Hierarchy Process (AHP) analysis to assess the importance and prioritization of these factors among relevant industry stakeholders.

• Journal of The Korean Association For Science Education
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• v.39 no.1
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• pp.13-33
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• 2019

The purpose of this study is to clarify the possibility of the character education and the concrete implementation process in the field of science education in accordance with the social demand for character education. Based on this purpose, the researchers tried to understand the specific character elements appearing in various science learning situations and to understand the qualities of each specific character elements that can be emphasized through science learning and the aspect of expression process in related learning situations. The researchers selected 11 students from the 7th and 8th graders in Seoul and developed and applied the 'Become a Science Teacher' mentor program in 2014 and 2015. Data collection was conducted through class recordings, mentor teachers' and assistant teacher's journal, artifacts, student journals, student portfolios, class listeners' essays for science class and analyzed qualitative data collected through constant comparison method. According to the result, we extracted 11 character elements and reorganized them into 16 specific character elements revealed in various learning situations based on the relationship between each character elements. The results of the study are eight specific character elements that can be emphasized through science learning and related learning situations. The eight specific character elements are 'responsibility for teaching behavior due to hierarchy of scientific knowledge structure, communication for forming scientific concept, empathic concern based on science learning experience, cooperation for promoting rationality of inquiry method, positive perception of scientific endeavor, respect for scientists' attitudes toward research, confidence in future scientific research, persistence in trial and error'. Based on the results of this study, we proposed the research methods of character in the field of science education in the future.

• Composites Research
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• v.36 no.1
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• pp.1-15
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• 2023

Demand for energy consumption reduction is increasing according to the development expectations of future mobility. Lightweight structural materials are known as a method to reduce greenhouse gas emissions and improve energy efficiency. In particular, fiber reinforced polymer composite (FRP) is attracting attention as a material that can replace existing metal alloys due to its excellent mechanical properties and light weight. In this paper, industrial applications and research trends of carbon fiber reinforced composites (CFRP, carbon FRP) and self-reinforced composites (SRC) were reviewed based on the reinforcement, polymer matrix, and manufacturing process. In order to overcome the expensive process cost and long manufacturing time of the epoxy resin-based autoclave method, which is mainly used in the aircraft field, mass production of CFRP-applied electric vehicles has been reported using a high-pressure resin transfer molding process including fast-curing epoxy. In addition, thermoplastic resin-based CFRP and interface enhancement methods to solve the recycling issue of carbon fiber composites were reviewed in terms of materials and processes. To form a perfect matrix-reinforcement interface, which is known as the major factor inducing the excellent mechanical properties of FRP, studies on SRC impregnated with the same matrix in polymer fibers have been reported. The physical and mechanical properties of SRC based on various thermoplastic polymers were reviewed in terms of polymer orientation and composite structure. In addition, a copolymer matrix strategy for extending the processing window of highly drawn polypropylene fiber-based SRC was discussed. The application of CFRP and SRC as lightweight structural materials can provide potential options for improving the energy efficiency of future mobility.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.1-21
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• 2020

With the rapid development of artificial intelligence technology, various techniques have been developed to extract meaningful information from unstructured text data which constitutes a large portion of big data. Over the past decades, text mining technologies have been utilized in various industries for practical applications. In the field of business intelligence, it has been employed to discover new market and/or technology opportunities and support rational decision making of business participants. The market information such as market size, market growth rate, and market share is essential for setting companies' business strategies. There has been a continuous demand in various fields for specific product level-market information. However, the information has been generally provided at industry level or broad categories based on classification standards, making it difficult to obtain specific and proper information. In this regard, we propose a new methodology that can estimate the market sizes of product groups at more detailed levels than that of previously offered. We applied Word2Vec algorithm, a neural network based semantic word embedding model, to enable automatic market size estimation from individual companies' product information in a bottom-up manner. The overall process is as follows: First, the data related to product information is collected, refined, and restructured into suitable form for applying Word2Vec model. Next, the preprocessed data is embedded into vector space by Word2Vec and then the product groups are derived by extracting similar products names based on cosine similarity calculation. Finally, the sales data on the extracted products is summated to estimate the market size of the product groups. As an experimental data, text data of product names from Statistics Korea's microdata (345,103 cases) were mapped in multidimensional vector space by Word2Vec training. We performed parameters optimization for training and then applied vector dimension of 300 and window size of 15 as optimized parameters for further experiments. We employed index words of Korean Standard Industry Classification (KSIC) as a product name dataset to more efficiently cluster product groups. The product names which are similar to KSIC indexes were extracted based on cosine similarity. The market size of extracted products as one product category was calculated from individual companies' sales data. The market sizes of 11,654 specific product lines were automatically estimated by the proposed model. For the performance verification, the results were compared with actual market size of some items. The Pearson's correlation coefficient was 0.513. Our approach has several advantages differing from the previous studies. First, text mining and machine learning techniques were applied for the first time on market size estimation, overcoming the limitations of traditional sampling based- or multiple assumption required-methods. In addition, the level of market category can be easily and efficiently adjusted according to the purpose of information use by changing cosine similarity threshold. Furthermore, it has a high potential of practical applications since it can resolve unmet needs for detailed market size information in public and private sectors. Specifically, it can be utilized in technology evaluation and technology commercialization support program conducted by governmental institutions, as well as business strategies consulting and market analysis report publishing by private firms. The limitation of our study is that the presented model needs to be improved in terms of accuracy and reliability. The semantic-based word embedding module can be advanced by giving a proper order in the preprocessed dataset or by combining another algorithm such as Jaccard similarity with Word2Vec. Also, the methods of product group clustering can be changed to other types of unsupervised machine learning algorithm. Our group is currently working on subsequent studies and we expect that it can further improve the performance of the conceptually proposed basic model in this study.

• Journal of Nutrition and Health
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• v.51 no.2
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• pp.186-198
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• 2018

Purpose: This study was performed to evaluate the utilization of a current national Food Composition Database (FCDB) and to investigate demand for nutrients that should be added or supplemented in order to expand the national FCDB. Methods: Surveys were constructed based on the utilization of FCDB, use of a food and nutrition analysis program, utilization and importance of nutritional ingredients, and nutritional ingredients desired to be supplemented in the national FCDB. Self-administered surveys were obtained from 349 food and nutrition specialists, including dietitians, nutrition teachers, food industry workers, professors, and researcher. Results: Exactly 73.6% of respondents used the FCDB, and 90.5% experienced using various food and nutrition analysis programs. Professors and researchers frequently utilized protein, carbohydrate, and lipid nutrients in the FCDB. Among vitamins, vitamin C, vitamin A, and vitamin D were frequently used. Among minerals, sodium and calcium were highly used. Among the subjects, 17.4% of subjects have used phytochemical DB. Carotenoids, anthocyanins, and isoflavones among phytochemicals were frequently used, in that order. Respondents desired an additional data on sugars, vitamin D, folic acid, selenium, iodine, dietary fiber, vitamin $B_{12}$, and carotenoids in the FCDB. Conclusion: The survey results indicate that the current FCDB is actively used for various purposes, although it is necessary to construct a national nutrition database with additional nutrients.